Table 1 Expected offspring phenotype as a function of their own genotype and the genotype of their mother
Offspring genotype
A1A1A1A2A2A2Maternal litter average
Maternal genotype
 A1A1+am +ao Embedded Image+am +do Embedded Image+am + p2do + p1ao
 A1A2+dm +ao Embedded Image+dm +do Embedded Image+dm –ao Embedded Image+dm + Embedded Imagedo + Embedded Imageao(p1p2)
 A2A2–am +do Embedded Image–am –ao Embedded Image–am + p1do – p2ao
Offspring average+ao + p2dm + p1am+do + Embedded Imagedm + Embedded Imageam(p1 – p2)–ao + p1dm – p2am
  • Each cell gives the direct (subscripted “o”) and maternal (subscripted “m”) effects that contribute to the phenotype of an offspring as a function of the maternal–offspring genotype combination. The cells with dashes exist under Mendelian inheritance. The expected phenotypes of the offspring associated with each maternal genotype are given as row means and the average phenotype of each offspring genotype is given by the column means. The frequencies of each maternal–offspring genotype combination are shown in parentheses (Wade 1998).